The Study Of The Association Between Gestational Diabetes Mellitus And Tumor Necrosis Factor-alpha Gene Polymorphism

BackgroundDiabetes is a clinical syndrome induced by the inheritance and environment. With the improvement of the living level and the development of industrialization, more and more people suffer from the disease at present. Many researchers have found that type 2 diabetes is related with tumornecrosis factor-alpha (TNF- a ) gene. Until now, the correlation of gestational diabetes mellitus (GDM) with TNF- a alleles polymorphism is not reported.ObjectiveThe study was to investigate allelic frequency of TNF- a in GDM of Han ethnicity in north China and to determine whether there is a specific allele of TNF- a association with GDM susceptibility. At the same time, the study wasdesigned to explore the relationship TNF- a allele with body mass index(BMI) , plasma levels of TNF- a and insulin resistance (IR). The purpose of this study was to establish a foundation for further investigation of the pathogenesis and therapy of GDM.MethodsThirty-five GDM women enrolled into the study group, thirty-five normalpregnant women were selected as control group, and all pregnant women were primiparae with single fetus. Exclusion criteria were the presence of infection, inflammatory, hypothyroidism, endocrine disease other than diabetes, or the use of anti-obesity drugs. Four milliliters venous blood weretaken from all women in the two groups. Genomic DNA was extracted from venous blood. By using PCR-RFLP, we detected the distribution of TNF- apromoter alleles frequency in these subjects. Plasma TNF- a levels and insulin levels were measured by radioimmunoassay.Results1. There was a significant increase of "A" alleles frequency of TNF- a promotor -308 gene in GDV1 women compared with control group object (67.2% vs 32.8%, P<0.01) and an increase of the "AA+AG" genotype was observed in GDM group (68.5%vs37.2% , P<0.01).2. In GDM group, the patients carrying the "AA+GA" genotype had a higher BMI (31.4 + 0.5 vs 22.7 + 0. 6, P<0. 05), plasma TNF-a levels (47.8 + 19. 1 vs 20. 7 13. 1, P<0. 05 and a lower insulin sensitivity [HOMA(Ri)] (7.4 2.0 vs 3. 9 1.3, P<0. 05) compared with those carrying the other genotype ("GG").Conclusion1. There were -308G -A polymorphism of tumor necrosis factor-alpha promoter gene in the Han nationality women in north China.2. The alleles "A"' of TNF- a was regarded as the susceptibility of GDM women in north China.3. TNF- α -308 gene polymorphism was involved in the pathophysiology of insulin resistance.